nanog mailing list archives
Re: REMINDER: Leap Second
From: "John Levine" <johnl () iecc com>
Date: 26 Jan 2015 18:20:20 -0000
Barney Wolff <barney () databus com> wrote:
On Sun, Jan 25, 2015 at 06:42:51PM -0500, TR Shaw wrote:That made the transformers smaller/cooler and more efficient. I seem to remember a 195 as well but maybe itis just CRS. Google says the 360/195 did exist. But my baby was the 360/95, where the first megabyte of memory was flat-film at 60ns, which made it faster than the 195 for some things. ...
The /95 was a /91 with a megabyte of thin film memory, which was both much faster than core (120 vs 780 ns cycle time) and much more expensive (7c rather than 1.6c per bit.) The /195 was a /91 reimplemented in slightly faster logic with a 54ns rather than 60ns cycle time, and a cache adapted from the /85. I can easily believe that for programs that didn't cache well, the /95 with the fast memory would be faster. IBM lost money on all of them and eventually stopped trying to compete with CDC in that niche. See alt.folklore.computers (yes, usenet, reports of its death are premature) for endless discussion of topics like this. R's, John
Current thread:
- Re: REMINDER: Leap Second, (continued)
- Re: REMINDER: Leap Second Karsten Elfenbein (Jan 25)
- Re: REMINDER: Leap Second Ken Chase (Jan 25)
- Re: REMINDER: Leap Second Joe Klein (Jan 25)
- Re: REMINDER: Leap Second Karsten Elfenbein (Jan 25)
- Re: REMINDER: Leap Second John Levine (Jan 25)
- Re: REMINDER: Leap Second Valdis . Kletnieks (Jan 25)
- Re: REMINDER: Leap Second Ken Chase (Jan 25)
- Re: REMINDER: Leap Second Stephen Satchell (Jan 25)
- Re: REMINDER: Leap Second Barney Wolff (Jan 25)
- Re: REMINDER: Leap Second TR Shaw (Jan 25)
- Re: REMINDER: Leap Second Barney Wolff (Jan 26)
- Re: REMINDER: Leap Second John Levine (Jan 26)
- Re: REMINDER: Leap Second Barry Shein (Jan 26)